1. Field of the Invention
A present invention relates to a power management system and a power management method in a computer system including a plurality of computers.
2. Description of Related Art
In recent years, since power consumption has been rapidly increasing due to development of high performance of a single computer, the power consumption of an entire computer system such as a blade server system including a plurality of computers has been significantly increasing. Consequently, there is a strong demand for reducing maximum power consumption of the entire computer system while guaranteeing a certain performance (power) for each computer.
An example of a technique for reducing the power consumption of the entire computer system to less than or equal to a certain value while guaranteeing a certain performance (power) for the computer which is included in the computer system, is described in Patent Document 1. In a power management system described in Patent Document 1, in order to keep power consumed by a blade server including a plurality of blades, each of which operates like a computer, within a range of maximum power which can be supplied from a power supply box, an operating frequency of a CPU of the blade is limited.
For example in the Patent Document 1, in a blade system configured with three blades, a supplied power condition is set in which the power consumption of the entire blade server is held within the range of the maximum power which can be supplied, if the operating frequency of the CPU of one blade is set to 100% of a maximum value and the operating frequencies of the CPUs of the other two blades are set to 50% of the maximum value.
The supplied power condition is set according to a priority set to each blade, the operating frequency of the CPU of one blade is controlled to be less than or equal to 100%, and the operating frequencies of the CPUs of the other two blades are controlled to be less than or equal to 50% so that the supplied power condition may be satisfied during system exemplary operation.
Moreover, an operating status of the blade with the CPU operating frequency of 100% is monitored. If the blade has kept on operating at the operating frequency less than or equal to 50% for more than or equal to a certain period, then an upper limit of the operating frequency of the CPU of the blade is changed to 50%, and instead of changing the operating frequency of the CPU to 50%, among the other two blades, the upper limit of the operating frequency of the CPU is changed from 50% to 100%.
[Patent Document 1] Japanese Patent Laid-Open No. 2005-202506